It’s believed a mysterious fish kill in Okanagan Lake last summer may be responsible for a plunge in numbers of shore-spawning kokanee last fall.
Only 78,000 shore spawners were counted, compared to a record high last year of 276,000.
Stock assessment biologist Paul Askey with the natural resource operations ministry says something was “weird” this fall.
“I have a feeling we missed something this year (in the count).”
However, there were thousands of fish found dead on the lake this summer, and they have no way of determining how many dead ones didn’t show up, so what the real numbers were, he said.
“There could have been more lost there,” he added.
He’s confident that in-lake conditions can support the fish, but he says he gets the sense that stream restoration does result in increases.
For instance, he noted that the number of stream spawners in the man-made Mission Creek spawning channel in Kelowna were 6,600, which is average to above-average, while numbers in the main stream were 6,300.
“That gives us a clue that stream habitat work is worthwhile.”
In total there were 20,000 stream spawners this year, up slightly from the 18,000 counted last year, but far below the numbers counted in 1991, when more than 94,000 were counted in Mission Creek alone.
He admitted that the numbers in Okanagan Lake this year were disappointing, although he said the numbers in both Kalamalka Lake and Skaha Lake were fine this year.
“We need to keep working on stream habitat,” he said.